Manufacture Embossings:Acoui: The town in Italy where the Insulators where madeAT:Alta Tensione (High voltage)BT:Bassa Tensione (low voltage)CA:Cavo in Alluminio (Cable in Aluminum)FS:Ferrovie dello Stato (Italian State Railroad Co.)MT: Media Tensione (medium voltage)M: (Unknown)S: (Unknown)T: (Unknown)UNES:UNione ESercizi elettrici (old private electric co.)V: (Unknown)1xx, 2xx, 3xx series: Seen on Multi Parts, the fist Number is how many parts. for the 1xx it is shaped like a Multipart but is a Unipart (Example the MIVA 1212)